Information from close family or friends is crucial in a missing person investigation.

“I feel like we lost any chance of getting any unanswered questions answered at that point,” said Michigan State Police Detective Sgt. Lisa Gee-Cram. “And that’s to either extreme. He knew her best. He lived with her and knew her habits.”

Cassidy was interviewed by Jackson County Sheriff’s deputies while in jail. He denied involvement in his girlfriend’s disappearance, according to earlier reports. He also left behind a hand-written note, in which he titled it “My Last Testament and Will,” before committing suicide, Undersheriff Chris Kuhl said.

In the letter, Cassidy expressed dislike for Betty and James Whitehill, and outlined who should receive his possessions. He also denied killing Stiles or knowing anything about her disappearance, Kuhl said.

“I hope you are OK wherever you are. I love you,” he writes. He also mentions Stiles’ children: Ayla, 9 and Nathan, 16, calling them “beautiful.”

Katie Rausch | Jackson Citizen PatriotJames Whitehill looks on as his wife, Betty, talks about the disappearance of her daughter, Tonia Stiles.

The Jackson County Sheriff’s Office declined to release the letter in its entirety due to ongoing civil litigation surrounding Cassidy’s death.

Betty Whitehill said police told her Cassidy underwent a polygraph test while in jail and failed it. Gee-Cram declined comment when asked about it, citing a confidentiality agreement signed by Cassidy. His mother, Lori, declined comment when reached by phone earlier in the week.

Police believe Stiles is dead and are treating the search as a recovery effort. Stiles, whose identification is in a national registry for missing persons, has not popped up anywhere around the country. Family and friends fear Stiles is dead, saying she would have never left her children alone.

“She didn’t run off, she didn’t go nowhere,” said Lynn Altvater, a friend and former co-worker at the Napoleon Cafe, 6816 W. Brooklyn Road. “Ayla always went with her. She was very protective of her kids.”

Altvater met Stiles in 2003 while dating Stiles’ stepbrother, James Musbach. She said they joked around a lot and looked out for each other. A week or two before Stiles’ disappearance, Altvater said Tonia took her behind her home and outlined plans she and Scott had made to clean out the swamp and turn it into a pond.

“She said they were going to put a raft in the middle and make a little boat,” Altvater said with a smile. “And then she joked that somebody could kill somebody back here and bury them in this pond and nobody would know. I said, ‘Whatever, Tonia.’ She always talked crazy stuff.”

Three days later, Altvater said she dreamed Stiles was missing and was found dead in the pond. Two days later, she said, Stiles really did disappear.

Altvater said Cassidy’s behavior was odd after Stiles’ disappearance. She recalled one time he stopped by her Napoleon Township home, looking for Stiles’ brother, Patrick Whitehill.

“Scott was always (polite) and looked at you,” Altvater said. “This time he walked up to the door, looked down and wouldn’t even look at me. He acted funny, then walked away.”

Search and rescue crews have combed bodies of water in the area, including Wolf Lake, to no avail. Helicopters have been used twice, with a K-9 unit out as recently as last spring.

Two weeks ago, Michigan State Police urged outdoorsmen to keep an eye out for anything suspicious this hunting season. So far, credible new tips have been few and far between. Gee-Cram said the department has received several tips, but many are second or third-hand knowledge.

“They hear something and become their own little detective and report back to me,” she said. “That does me no good. I need to be able to ask follow-up questions.”

Despite the attention, the many searches by friends and family, no sign of Stiles has been found. The home on Orban Road still sits vacant. Her kids, living with their respective dads, hope one day they will find out what happened to their mother.

“I do believe we will find her,” Gee-Cram said. “I want closure for the family, primarily for her children. That’s really the biggest hang up from people who knew her ... she wouldn’t have done this to her kids.”

Anyone with information is asked to call the Michigan State Police at 780-4580 or the Jackson County Tip Line at 787-0212.